Hack #16 Fresh water overflow drain valve.

If your fresh water tank seems to be losing water after you fill it, the problem may be that the overflow tube has dropped and is siphoning water off the top.
At the least, you will lose some due to sloshing around while going down the road. (A lot if you drive through NJ or PA).
Adding a valve to the end of it can stop the problem but you must be aware of the issues. You need to open the valve when you are filling the tank to allow air to escape and make room for the water.
You may also need to open it if the temperature rises drastically in order to prevent too much pressure from building up.

It’s really quite easy.

Purchase one 1/2″ “Sharkbite” shut off valve. If you get the 1/2″ to GHT (garden hose thread), you can attach a hose to it to drain the overflow away from the trailer but it’s not necessary.

Locate the fresh water overflow hose. It is underneath near the fresh white water tank drain and about center – in front of the wheels.
Unscrew the collar and slip it over the hose and up then push the compression fitting of the valve into the drain hose.
Drop the collar back and screw it firmly to the valve fitting.
That’s it
Now you can prevent any problems with losing water from the fresh water tank through the overflow hose.